This Competing Continuation proposal for "biomedical and health informatics" (B&HI) brings together faculty and students in four universities and five major academic teaching hospitals in the Boston area. Since our previous renewal five years ago, B&HI is becoming an increasingly mainstream aspect of our academic medical centers, pervading most aspects of (a) research, across a wide spectrum from molecular/genomic to population-based studies; (b) clinical practice, and education. Moreover, research, practice, and education are all becoming large, distributed, even "virtual" enterprises, as a result of which their management requires attention to infrastructure and enabling technologies. A number of broad development initiatives in the Boston area are now bringing B&HI specialists and domain experts together - in bioinformatics, educational technology, image-based systems, shared information repositories, knowledge-based clinical practice, machine learning, consumer health, and other areas. We have experienced a dramatic growth in faculty and students active in B&HI. Primary B&HI faculty and research have more than doubled since our combined training program began 10 years ago. We have been very successful in recruiting bright, creative, and energetic trainees. Many of our former trainees have gone on to academic or health information system leadership positions throughout the United States. This proposal seeks to build on our experience and on the various new initiatives, to provide a multi-faceted, coordinated, training program to prepare B&HI professionals for successful careers in this field. The program is administered through the joint Harvard-MIT Division of Health Sciences and Technology (HST), which provides an academic home for B&HI, the ability to make primary and secondary faculty appointments, cross-registration of courses, and two degree programs in B&HI. Three other degree programs are also available to trainees. Trainees typically have dual appointments in HST and in one of seven primary informatics research and development units, based at Harvard, MIT, or at teaching hospitals. Collaborative projects involve a number of other participating entities. A total of 25 positions (5 predoctoral, 20 postdoctoral) is requested in the first year, representing a limited increase of 4 positions since 10 years ago (increasing by one more position the following year).